One of the biggest surprises, for me at least, was that short, sharp questions are not among the best-performing subject lines -- particularly if they come from a unknown person and appear like a cold call. A question mark even makes it worse, the research finds. Typically, a question-based email saw open rates and reply rates drop by around 10% compared to an email marketing average.
The research also showed that greetings such as "Hi" and "Hey" also turn recipients off, seeing a large drop in engagement against an industry average. The researchers conclude that these popular email headers with such personal greetings are instantly recognised as a way to introduce a sales message, and so the emails are discarded.
So, if those are surprising discoveries, so too are the conclusions about what does work. According to the researchers, putting some numbers, a metric or piece of data of some sort in the title are top performers because people like a firm steer based on real-life data. Also -- and this is the one that surprised me the most -- using capitals as part of a subject header is a winner for boosting engagement.
The research would suggest, then, that email recipients are now accustomed to quick questions trying to prompt a response and greetings trying to get a sales message to be opened. However, it appears that attention is won by adding a statistic, or some kind of number, to an email header with a proportion of the subject line in capital letters.
It may not fit in with every brand's findings, but it's certainly a result that many email marketers would not have expected, so it might just pay to try the tactics and see if there is any uplift in open rates and engagement.